Mixing Layer Height Determination Based on Celiometer Backscatter Data

Abstract

Knowing the height of the planetary boundary layer (PBL), also known as the mixing layer, is an important factor for the aviation meteorology as well (beside pollutant dispersion modeling or air quality monitoring) since it determines the height of the low-level cloud base related to the boundary layer. Due to the aerosol concentration difference between the planetary boundary layer and the free troposphere, it is possible to continuously detect the height of the mixing layer (with a sufficiently sensitive celiometer), which can help in achieving better clouds nowcasting. Information regarding the thickness of the PBL is particularly important for aircraft takeoff and landing. We shall review the methods used for determining the thickness of the mixing layer. Then we shall provide the data measured at Budapest (12843) and compare them to the radiosonde detections and the formerly nationally used standard method. The results support the suitability of the Jenoptik CHM 15 celiometers (used at the OMSZ stations) for PBL research and airport information providing services.